隧道進(jìn)洞實(shí)施性施工方案英文版2014.11.20再次修改

1、 SINOHYDRO CORPORATION LIMITED Document No.RevisionDatePage No.:MS-010/VII Section0020November201411 of 9SECTION VII TUNNEL “PRESEKA”Methodology Statement of Entering Inside of the Tunnel TubesDocument No. : MS-010/VII Section, Revision 00Date : 20November 2014RevisionDatePrepared ByReviewed byAppro

2、ved ByContents1. Project overview22. Geological condition22.1 Investigation work22.2 Geological condition of inlet22.3 Geological condition of outlet32.4 Conclusion43. Suggestion statement44. Pipe roof construction procedure and workmanship44.1Preliminary Works44.2 Advanced support measures of tunne

3、l entrance54.2.1 Pipe roof constructions Pipe roof constructions Grouting85. Excavation method of entering tunnel tubes96. Configuration of construction machinery and workforce9 Methodology Statement of Entering inside the Tunnel Tubes1. Project overviewAccording to the data, the lef

4、t tunnel inlet elevation is EL.910.435m and tunnel outlet elevation is EL.960.039m.the right tunnel inlet elevation is EL.909.906m and tunnel outlet elevation isEL.959.522m. The tunnel excavation radius is 5.25m and cutting height is 8.05m. The formed tunnel clearance is 9.41m6.45m. 2. Geological co

5、ndition2.1 Investigation workA horizontal borehole of 25m was performed for both tunnel for both inlet and outlet as a predict investigation work to guide of the work.2.2 Geological condition of inletIn general, from a geological point of view, they are represented with two lithologic members:（1）Sqs

6、e sericite-quartz schistsThe color of the light to dark gray, black, greenish, yellowish. They have a schist texture and lepidoblastic structure.They are mostly made of serecit and quartz, and in greater quantities there are represented chloride and epid. As a by-occurring there are zircon and tourm

7、aline. They are often limonitizaded after foliation. with RQD about 8%, a very prominent fissure and fragmented, with the presence of clayey sand material as well as in the intervals discernible limonitization. The main crack system is the system by the extension, but there are several other routes

8、(attachment 1). RMR and GSI are calculated as: 0 (no sample for test due to very highly fractured) +3 (RQD25%) +5 (the spacing of discontinuies is lower than 60mm) +0 (joints were filled with clay or even open joints)10 (the rock is damp)-12( the discountinuities is about 70to the tunnel axis)=6 ver

9、y poor rock(V).SCR = 1 (smooth) + 1 (highly weathered) + 2 (filled with clay)GSI = 27（2）Sgr - graphitic schistsThe color of the dark gray or black, with a schist texture. They are easy to tear after foliation, and they show more compactness than their predecessors. In the composition, in addition to

10、 splashed quartz grains they contain graphite material (dusty) which is impregnated throughout the whole rock. Limonitization is often present. Common to them is to be more or less mutually interfered, with rare sharp edges, EP 290 / 20-30 or they extend NW-SE from the road to the SW, they are tecto

11、nised and fragmented in small pieces, and in some places up to clayey sand material.RQD = 15% shows a weak compactness of rock masses. It is easy to break after foliation, and they have other crack routes. RMR and GSI are calculated as:0 (no sample for test due to very highly fractured) +3 (RQD25%)

12、+5 (the spacing of discontinuies is lower than 60mm) +10 (the surface of joints is smooth)10 (the rock is damp)-12 ( the discountinuities is about 70to the tunnel axis)=16 very poor rock(V)SCR = 1 (smooth) + 3 (moderately weathered) + 4 (filled with iron oxide)GSI = 382.3 Geological condition of out

13、letIn general, from a geological point of view, they are represented with three lithologic layers: Sericit-quarzt , Graphite and Chlorite-sericite schists.（1）Sqse sericite-quartz schisThe color of the light to dark gray, black, greenish, yellowish. They have a schist texture and lepidoblastic struct

14、ure.They are mostly made of serecit and quartz, and in greater quantities there are represented chloride and epid. They are often limonitizaded after foliation. RQD is very low, due to its decomposition (non-compactness) fragmentation. The RMR and GSI are calculated as following: 0 (no sample for te

15、st due to very highly fractures) 3 (RQD /Rock quality design 25%)5 (the spacing of discontinuities is lower than 60mm)10 (joints were filled with clay or even open joints)10 (the rock is damp) -12 (the Discontinuities is about 70 to the tunnel axis /axle) = 18 - Very poor rock (V)GSI = 15 (geologica

16、l strength index) SCR= 1 (smooth) +1 (highly watered) + 2 (filled with clay) SR 10 SR 20（2） Sgr - graphitic schistsThe color of the dark gray or black, with a schist texture. They are easy to tear after foliation, and they show more compactness than their predecessors. In the composition, in additio

17、n to splashed quartz grains they contain graphite material (dusty) which is impregnated throughout the whole rock. Limonitization is often present. Common to them is to be more or less mutually interfered, with rare sharp edges, EP 280 / 25 or they extend NW-SE from the road to the SW, they are tect

18、onised and fragmented in small pieces, and in some places up to clayey sand material.RMR and GSI are calculated as following:0 (no sample for test due to very highly fractures) 3 (RQD /Rock quality design 25%)5 (the spacing of discontinuities is lower than 60mm)10 (joints were filled with clay or ev

19、en open joints)10 (the rock is damp) -12 (the Discontinuities is about 70 to the tunnel axis /axle) =18 Very poor rock (V)GSI = 15 (geological strength index) SCR= 1 (smooth) +1 (highly watered) + 2 (filled with clay) SR 10 SR 20（3）Scose -chlorite-sericite schists Rocks with very low strength, crack

20、ed, soft caolinized with greenish color.2.4 Conclusion A value of 40-50% of RQD is given in the given document while its actually less than 10%.With RMR system, the rock is classified into IV rocks but its type V in fact. All engineering methods for rock mass as excavation and supporting shall be mo

21、dified into the special treatment for very fractured rock even as for rock fragments. 3. Suggestion statementAccording to the actual geological condition, within the 24 meter of entering tunnel tubes at inlet and outlet parts of tunnel( left carriage Km18+294.5Km20+310.5,and right carriage Km18+279.

22、5Km20+274.5,the suggstion is that using big pipe roof(canopy) to advanced support and designd support be constructed at four portals within 24m of entering tunnel tubes. If after entering the tunnel, the similar condition occurs, the small pipe roof (canopy) and preceding rock anchor could be used.

23、4. Pipe roof construction procedure and workmanship 4.1Preliminary Works （1）Surveying preliminary Drawing the construction shopdrawing is according to the design construction drawings. （2）resource preliminary It is equipped with adequate personnel and equipment according to the construction general

24、plan, construction period and strength, for guaranteeing the equipment with good performance. Construction material should be planned, purchased and restored in advance for guaranteeing the material to go with the construction. 4.2 Advanced support measures of tunnel entrance4.2.1 Pipe roof construc

25、tions Before construction pipe roof, the frontal slopes should be constructed according to the design, and then continuing to construct the pipe roof. The pipe roofs are advanced-support measures to be implemented at fours portals. The length of one pipe roof is determined 24m.The pipe roof will be

26、practiced with the pipe jacking method. After competing to excavate the tunnel portal areas, the drilling operation platform of the pipe roof should be installed, and the location of the holes should be lay out. Pipe roof layout diagram is shown:Drawing 4-1 Pipe roof sketch Drawing 4-2 longitudinal

27、layout of advanced support for pipe roof The diagram of the pipe roof quantities Table 4-1LocationItemsThe diameter 89 pipe roof（m）Drilling holes（m）Grouting（m3）Inlet part of right tunnel 74474421.2Outlet part of right tunnel 74474421.2Inlet part of left tunnel 74474421.2Outlet part of left tunnel744

28、74421.2Amount29762976.1 Pipe roof constructions The pipe roof should be complied with the design to construct. The drilling machine should be accuracy control. After drilled a hole, a steel bar should be embedded. The construction sequence is from the up to the bottom. Before constructing a

29、rch of the pipe roof, the construction platform must be installed.After embedded all Steel Pipe, the high-pressure wind will be used for removing inside of pip. Completed, Hydraulic grouter carries out the grouting pipe roof. The detail procedures are as following:Pipe roof construction workmanshipS

30、teel pipe processingPreliminary workNext circulationGrouting canopy pipeCleanup the pipesEmbed the steel pipesPilot holeDrilling rigs are readyGrouting configurationHydraulic grouter be ready Grouting shall be used cement mortal to grout. The grouting is accordance with the site geological situation

31、 and the effectiveness of holes, the repeatedly grouting should be practiced by adjusting the grouting pressure to fill the steel inside and the interspace around the steel. （1）Steel fabrication and processing The external diameter is 89mm of the steel, and the wall thickness is 6mm, which is produc

32、ed with the hot-rolled steel pipe. Steel wall is perforated with holes plum-type arrangement,10-16mm hole diameter and hole spacing 1520cm; The remaining length of undrillings stoppage section of pipe tail should be at least 1m. The remaining length of the external steel should be more than 0.2m. Dr

33、awing 5-3 Steel pipe sketch（2）Construction pipe roof Drilling holes: According to the design position to construct, the diameter of the drilling hole is 110mm, the loop spacing is 40cm, rise up 13 from the tunnel axis. The vertical axis of the drilling rig should be accurate control to ensure the po

34、sition of the holes. After completing a hole, a steel bar should be embedded. the clinometers will be used to survey the drilling degree of skewness. Any error, please correct in time. Cleaning holes: 89mm core barrel should be used to clean holes, cleaning the slag inside of the hole and smooth the

35、 hole tube. The length of the core barrel should not less than 3m, which is better for a more length. Have some problem to input the barrel, continue to clean several times, at the same time, the high pressure wind also could be used to clean, until it is clean. Pipe roof installation: on the condit

36、ion that the hole is stable, directly strike the pipe roof into the designed hole. On the contrary, unstable, the pipe roof and the drill aiguilles are practiced at the same time. If there is some problem to install, firstly check. If it is necessary to renew the hole, cleanup and then reinstall. Ge

37、ological investigation: the drilling section geological condition will be judged according to the speed of the drilling, investigative coring and driller pressure, and keep in record in time. When the pipe roof has been installed in drilling rigs, aiming at the hole, low-speed propulsion pipe, the i

38、mpact force should be controlled at the 1.82.0MPa; the propulsion force should be control at 4.06.0MPa.Blockage the steel: First blocking the holes void with linen strips, after tightening with a circular wedge ring and finally the wedge ring is welded to the pipe roof. Grouting The sequence

39、of grouting should comply with the principle: “first both sides and then in the middle” and “from thin to thick”.Process flow diagrams of the pipe roof groutingRenovate pipe, re-groutingDrilling holesInstallation the holesConnectionConsequenceGroutingAdjust groutEffetenessGrouting from the entrance

40、at a time, to make full dense grout inside the pipe, during grouting, when the grout outflow from the vent hole, make the final pressure grouting, it doesnt terminate until reach the design grouting pressure or design grouting, and then close it valve. Grouting end criterion: the grouting should be not end until meet the design grouting pressure and not less than 15 minutes.After completing to grout, timely cleanup the